Gas pilot arrangement for burner apparatus



May 22, 1956 c. c. YOUNG 2,746,530

GAS PILOT ARRANGEMENT FOR BURNER APPARATUS I Filed Aug. 4, 1952 2 Sheets-Sheet 1 MEA/V6 GAS -Fl/EL CUTOFF Cyr!! Czczr/es Ya'zmg Ew ZLZL'E May 22, 1956 c. c. YOUNG 2,746,530

GAS PILOT ARRANGEMENT FOR BURNER APPARATUS Filed Aug. 4, 1952 l 2 Sheets-Sheet 2 j/ Char/e5 Young hw We @2mg fz HE 2 y United States i"attent y GAS PILOT ARRANGEMENT FOR BURNER APPARATUS Cyrii Charles Young, Kansas City, Mo. Application August 4, 17952, Serial No. 302,538

Y 7 Claims. (Cl. 158-11) oran annular gas burner unit is provided.

A gas pilot burner apparatus is provided and preferably includes arst pilot burner tube which extends adjacent the air chamber and includes port means to direct a pilot flame into an upper portion of the combustion chamber superjacent the reservoir tray. kAt this portion of the combustion chamber, an adequate supply of combustion supporting air has `been mixed with the vapors arising from the tray and no difculty is encountered in maintaining the gas pilot burner llame.` 4

A second pilot burner tube is extended through the air chamber and through the walls of the combustion chamber. The second pilot burner tube is provided with port means to direct a pilot llame into a lower portion of the combustion chamber towards the oil reservoir tray. The area surrounding the port means is usually vapor rich and, when a heavy quantity of vapors are rising from the tray, this `area `is likely to be deficient in combustion supporting oxygen. V

Inlet means are. provided between the air chamber and the secondy pilot burner tube so that the increased pressures prevailing in the ,air chamber will result in the suppljof an excess of combustion supporting air to the second pilot burner tube. Thus, the gas fuel supplied to thepilot burner tube will be premixed with anexoessive proportion of primary airthereby insuringburning of the pilot llame even though an oxygen deficient atmosphere exists inthe combustion zone immediately adjacent the supply of oil fuel in the reservoir tray.

y The second` pilot burner tubeisA also provided with port means -to direct a pilot flame upwardly in the general direction of the port means provided in the Erst pilot burner tube. This arrangement permits ignition and reignition of the oil burner pilot from' the pilot burner: tube' arranged adjacent the air chamber. v lt is an object of the present invention to provide a' gas pilot burner arrangementfwhich is easily fabricated from a` reducednumberof simplified componentsand which may be readily' utilized in burner units of conven tional design.

` Another object of the present invention is to providel afgas .pilot burner arrangement which'will be particularly useful ina combination gas-oil burner unit to insure ame stability during the off periods when oil is not being burned.. y

A.Au additionial object` of the present inventionis to providea safety pilot outside of the burner heat zone Y i y 2,746,530 ce Patented Mey 22,' 1956 2 which is completelyiaccessible for servicing and which will promote burner stability.

A further object of the present invention i's to provide a gas pilot burner arrangement which will insure ame stability andcomplete combustion of pilot gases.

Yet another object of the' present invention is to provide a gas pilot burner arrangement which is cooled by' a'n increased volume of gas and air owing therethrough.

- Yet another object ofthe present invention is to provide a gas pilotburner arrangement which will eliminate the possibility of gas fuel being conducted to the pilot burner being forced back through the conducting means during oil burner operation. i

Another object of the invention is to provide a pilot arrangement affording a reignition safety feature.

' Many other features, advantages and additional objects' of the `present invention will become manifest to those versed in the art upon making reference to the detailed description which follows and the accompanying' sheet of drawings showing a preferred structural embodiment of a burner unit including the gas pilot arrangement provided in accordance with the principles of the present` invention.

As shown on the drawngsf i Figure l is an elevational viewwith parts broken away' and with parts shown in cross section showing a burnerY unit incorporating the gas pilot arrangement of the present invention; i

Figure 2 is a fragmentary side elevational Viewl of the unit of Figure l;

Figure 3 is a'n enlarged fragmentary view of the port 0n the drawings:

For purposes of illustration, the principles of the pres-V ent invention are applied to` a vaporizing type oil burner indicated generally by the reference numeral 10.`

In theparticular embodiment shown by way of illustrative example, an oil reservoir is provided which takes the form of an annular vaporing tray 11 forming the bottom of a vaporizer compartment 12. A` supply of vaporizable fuel such as oil is furnishedto the tray through an oil supply line conduit i3 threaded into the` trayl as at`14 and communicating with a passageway 16yk formed in the bottom portion of the tray 11.

Onthe` inner annular edge of the tray 11 is mounted a* hub 18. The outer annular rim of the tray 11 is p'r'oV vided with a recess seating an annular sleeve 19 perforated as at 20.

A casing 2l forms together with the sleeve 19 and tlie `tray l1 an annular air chamber 22 which may be sup-k` plied with combustion supporting air through a duct 23' communicatingwith a conventional blower means.

A cap ring'. 24' is mountedon top of the casing l21 and the sleeve 19 and includesl a portion which overlies theH combustion chamber 12.

In the particular structural embodiment used for purposes `of illustration, a centrally located baille 26v is mounted atop the hub 18 and is arranged to deect the flames in the combustion chamber 12 upwardly and outwardly. It will be` understood, of course, that other vaporizing type oil burners may be used which employ an outer bale ring to direct the oil flames radially inwardly towards' the cen-ter of the burnerunit.

i It will also be" understood that'the burner unit lll is of i the type readily adaptable for conversion into a combi-V nation gas-oil burner since a gas nozzle g, as shown in dotted lines, Figure 1 can be arranged. to project a jet of gas fuel through the hub 18 and a different type of bafe B, shown in dotted lines, Figure l can be ernployed instead vof the baie 26 so as to act as av target flame spreader in the area superjacent the hub`18.

4 means S and mixing with the pilot gas supply is greatly increased to the extent that approximately 100% primary air is introduced with the gas. The amount of air y is sufficient to supply combustion of the pilot gas in an A bracket 27 is carried by the duct 23 and is attached adjacent the burner tube 33 by means of a bracket 36.

The leads to the' thermocouple 34 are indicated at 37 and it will be Vunderstood that the thermostatic safety cutoff operates in a conventional manner to operate a cut out means shown diagramrnatically and indicated by legend (Figure 2) operating to cut out the gas supply to the burner G in the event the pilot flame is extinguished.

The pilot burner tube 33 is provided with a port 38 arranged to direct a pilot flame against the thermocouple 34.` The tube 33 further includes a` port 39 which is arranged to .direct a pilot flame laterally to ignite a gas burner which is not utilized in the preferred embodiment herein illustrated. A third port 40 is provided in the burner tube 33 and is arranged to direct a pilot llame through a guide shield 41v mounted in rm assembly with the cap ring 24 by a plurality of fasteners 42 to a location generally superjacent the combustion chamber 12.

In accordance with the 'principles Vof the present invention, a second gas pilot burner tube 43 is connected to the gas supply line 31 and extends through an aperture 44formed in the casing 21, through the air chamber 22 and through an aperture 46 formedfin the sleeve 19. The

end of the pilot burner tube 43 extends into the combustion chamber 12 and is located `immediately adjacent the supply of oil contained in the vaporizer tray 11.

l oxygen deficient atmosphere.

The pilot gas premixed with an excess supply of primary air will burn in the oxygen deficient atmosphere since no secondary air will be required in the combustion zone immediately adjacent the supply of oil in the vaporizer tray 11.

The cap ring 24 of the exemplary design herein de- A. scribed is preferably notched as at 51 at a location in registry with the port 48 of the burner tube 43 and the flame emanating from the port 40 of the burner tube 33. Thus, under normal operating conditions, the pilot burner tube 33 and the pilot burner tube 43 Will operate to ignite or reignite one another. The structure provided thus affords a safe method'ofiguiting a vaporizing type oil burner since the pilot burner tube 33 operates as a safety pilot outside of the heat zone of the oil burner and yet incorporates into the burner unit the basic safety elements which are required for successful operation.

If the pilot arrangement described is utilized with a combination gas-oil burner unit, the main gas burner is ignited from a safety pilot of conventional design, yet,

Y the advantageous arrangement aorded by the inter- The burner tube 43 is provided with a port 47 ari ranged to direct a pilot flame downwardly into a lower portion of the combustion chamber and towards the supply of` oil fuel in the vaporizer tray 11. The tube 43 is further provided with a port 48 arranged to direct a pilot flame into an upper portion of the combustion chamber 12. in the general direction of the pilot flame emanating from the port 40 of the first pilot burner tube Port means are also provided in the end of the tube 43 between the ports 47 and 48 to direct a fan shaped pilot flame into the combustion zone immediately adjacent the supply of fuel in the vaporizer tray 11. In the particular embodiment shown, the last mentioned port means takes the form of a narrow slot 49 which extends between the ports 47 and 48, however, it will be understood that a plurality of aligned apertures could also be effectively provided.

When oil is being burned, the ports 47, 48 and 49 of the pilot burner tube 43 are located in an atmosphere delicient in air for combustion since most of the air for combustion in thevaporizing type burner unit 10 is introduced into the combustion chamber 12 near the top of theperforated sleeve 19. Under such conditions, there is 'insufficient secondary air surrounding the pilot burner tube 43 to support complete combustion of the gas fuel supplied to the pilot burner tube 43. Y

In order to provide suicient air to burn the pilot gas under such conditions, the present invention contemplates the location of a primary air intake means 50 on the burner tube 43 within the air chamber 22. .Since the air chamber 22 is 'normally pressurized by a fan or a i conventionalblower means during the oil burning cycle, the amount of -primary air passing throughthe air intake section of the jets from the gas pilot burner tube 43 and the gas pilot burner tube 33 insures that reignition of one of the pilot llames will eliminate the danger of an accumulation of unburned gases.

It may be noted that the air intake means 50 for the pilot burner tube 43 can conveniently comprise an apertured sleeve 52. It will be understood that the area of the ports may be made adjustable if desired, for example, through the provision of an additional sleeve (not shown) cooperating with thesleeve 52. The tube 43 is threaded as at 53 and a positioning guide 54 is provided between the casing and the tube 43 to firmly support the tube 43 in assembly with the burner unit 10. In order to remove the pilot apparatus, the clip 29 is loosened and the entire gas pilot supply line 31 may be retracted.

If the air chamber 22 is at normal atmospheric pressure, it will be understood that primary air for the burner tube 43 is induced through the air intake means 50 by the gas flow through the gas` supply line 31.

In the embodiment of Figures 5 and 6, the oil reser- Voir comprises a vaporizer tray 11a having a combustion chamber 12a adjacent'thereto. A supply of vaporizable fuel, such as oil, is furnished to the tray through an oil supplyconduit 13a. An outer casing 21a surrounds the burner unit and an inner sleeve 19a is provided above the vaporizer tray 11a so that'an air chamber 22a is pro- Y vided adjacent the combustion chamber 12a having a ame port or opening at the upper portion thereof.

The inner sleeve 19a is provided with spaced rows of diierent sized apertures 20a, the apertures being of small size at the bottom of the sleeve and increasing in size toward the upper end of the sleeve. Combustion sup- .porting air from the air chamber 22a passes into the combustion chamber lza'through the apertures 20a.

Supported on the outer casing 21a and the inner sleeve 19a is a casting forming an annular gas burner 56. The annular gas burner 56 has a hollow passageway 57 which receives a'supply of gaseous fuel from a gas duct 58 connected therewith. The annular hollow passageway 57 varies in cross sectional area so that a uniform supply of gas will be furnished from the duct 58 throughout the entire passageway 57 to a plurality of gas jets 59 arranged in an annular row.

The structure shown in the embodiment of Figure 5 Y includes a bracket 27a supporting a positioning clip 29a through which extends a gas supply line 31a having a pair of pilot burners on the end thereof.

chamber 12a.v A second gas pilot burner tube 43a extends atright angles to the first gasl burnertube 33a and projects into the` combustion chamber 12a. The' gas'pilot burner tubes .33a and 43ay are constructed identically with the gas pilot burner tubes 33 and S43 described above -iand arearranged to vdirect flames toward the llame port of the `combustion chamber whichserves as arcommonV objective sorthat the pilotswill ignite and reigniteqone another. In other words, the first gas pilot burner tube '33a is arranged to direct a pilot flame adjacent the gas burner 56 as well as into and toward the combustion chamber 12a and the second gas pilot burner tube 43a extending into the combustion chamber 12a not only projects a llame toward the fuel and vaporizer tray 11a,

but also projects a flame upwardly towards the llame port so that the two gas pilot burner tubes 33a and 443:11 will tend to ignite and reignite one another.

A flame carrier 41a is mounted on top of the casting 56 and assists in directing the ame from the first` gasv pilot burner tube 33a toward the flame port of the combustion chamber 12a. ltwill be noted that the gas jets 59 are ignited by the flame emanating from the first gas pilot burner tube 33a.

`Cutoff'means are indicated at 6i) andfunction to cut i off the supply of gas to the gas burner whenever a thermal unit v34a arranged adjacent the first gas pilot vburner tube l33a outside of the combustion chamber 12a is no longer heated by the first gas burner tube 33a, Thus, the apparatus of the present invention affords a very desirable safety feature since the thermal element 34a is located outside -of the heat zone in a completely accessible position affording ready serviceability.

Although various minor structural modifications' might be suggested by those versed in the art, it should be understood that l wish to .embody within the scope of the patent warranted hereon all such modifications Vas reasonably and properly come within the contribution to the. art.

l claim asmy invention: Y

l. Burner apparatus comprising, `an annularvaporizer trayhaving an upstanding perforated side wall, means to supply oil fuel to said tray, means forming an annular air chamber around said tray, means providing combustion supporting air to said airchamber for diffusion throughsaid wall, and a gas pilot assembly including scope of my f a` first burner tube adjacent said airchamber, a second burner tube extending horizontally through said air chambei" and said side wall, said second burner tube having air inlet means in said air chamber, said burner tubes formed to direct vjets of liame into adjacently spaced regions above said tray, said second burner tube having a first port to direct a pilot flame downwardly `towards and second ports to direct a fan shaped pilot flame over .said tray.

3.*Burner apparatus comprising, an annular oil tray,

` means to supply fuel oil to said tray, a perforated annular sleeve mounted on the outer ed'geof said tray, means forming together with said tray and said sleeve an annularair chamber adjacent said tray,v means to supply air to said chamber for diffused flow through said sleeve for supporting the combustion of fuel in said tray, and a gas supply line having a first pilot adjacent said air cham- `ber and a second pilot extending through said air chamber and through said sleeve, said first pilot having means operation of the oil burner all of its combustion sup-V lporting air through said air intake means in said air chamber.

4. A combination gas-oil burner comprising a burner unit having a combustion chamber, means including a vaporizer tray for selectively burning oil fuel in said combustion chamber, gas burning means including a gas nozzle for selectively burning a gas fuel, a first pilot outside of said combustion chamber directing a flame toward a region proximate the nozzle of the gas burning means to ignite the gas fuel, a second pilot extending into said combustion chamber and directing a flame towards a region proximate said tray of said oil burning means to heat and ignite the oil fuel in the tray, means providing a fuel gas supply connected to said gas burning means and including cutoff means in control of the gas fuel supply having a safety thermal actuating element adjacent said first pilot outside of said combustion chamber to cut off the gas fuel supply whenever said first pilot is extinguished, said pilots each having means directing a flame towards a common point to ignite and reignite one another.

5. In a burner unit, a vaporizer tray, means providing a supply of fuel to said tray, means providing a combustion chamber adjacent said tray, gas burning means including a main gas burner adapted to burn combustible gas, and a pilot arrangement consisting of a first pilot extending adjacent to and outside of said combustion chamber arranged to ignite the gasA fuel emanating from said vgas burning means, and a second pilot extending into said combustion chamber and arranged to heat and ignite the fuel in said tray, both of said pilots having means directing a pilot flame toward a'common point in said combustion chamber and operating to ignite and reignite one another, and means providing a source of gas fuel for said main gas burner controlled` by fuel cutoff means and including a thermal control element outside of said combustion chamber arranged to be heated by said rst pilot and adapted to operate said fuel cutoff means to cut off the supply of gas fuel to said main gas burner Whenever said pilot is extinguished.

6. A burner unit comprising means formed to provide a combustion chamber having a flame port and a pilot burner having a first pilot adjacent to and outside of said combustion chamber and directing a flame towards a region adjacent said flame port of said combustion chamber to ignite vapors in the area of said flame port, and a second pilot projecting into said chamber and directing a flame towards a region inside of said combustion chamber to heat and ignite fuel in the bottom of said combustion chamber, said second pilot having means directing a flame towards a region adjacent said flame port for igniting said first pilot and for being reignited by said first pilot, means providing a combustible fuel including a main gas burner and having cutoff control means including a thermalelement outside of said combustion chamber heated by said first pilot to cut off the supply of fuelv to said main gas burner whenever said first pilot is extinguished. p i

7. combination gas-oil burner comprising, a source of gas fuel supply, a main gas burner connected thereto and arranged to direct a gas flame upwardly, an oil burner tray having a bottom adapted to receive oil fuel from which combustible oil vapors rise upwardly, and a constant burner pilot assembly comprising a first pilot burner tube connected to said gas fuel supply and directing a jet ame toward a region above the gas burner unit to ignite the gas fuel, a second pilot burner tube con-Y nected to said gas fuel supply and directing a jet flame against the fuel oil to heat and ignite the oil fuel, andA References Cited in the file of this patent l 1,692,349 f 1,862,849 1,910,362 v1,926,218 t.

UNITED STATES `PATENTS u Quirozet al Nov. 20, 1928 Frame June 14, .1932 VPowers May 23, 1933 Valmore Sept. 12, 1933 Baker Dec; 12, 1939 Norman Oct. 20, 1953 

